Vibratory roller

ABSTRACT

A ground compacting machine of the kind having a vibratory compacting roller in which an oscillation exciter is located within the roller drum for causing the drum to vibrate, also has the means for driving the oscillation exciter and the means for driving the roller drum over the ground both located within the roller drum. The roller drum will usually be rotatably mounted on a non-rotating axle and the oscillation exciter and the roller drum may be driven from a common motor mounted on the axle. The oscillation exciter and/or the drum may be coupled to the motor through a centrifugal clutch, and the roller drum drive will usually include a reduction gear. The machine may comprise a single vibratory compacting roller having a steering bar connected to the axle, or at least two rollers and a machine frame mounted on the roller axles and providing a seat for an operator and means for steering the machine.

United States Patent Vural VIBRATORY ROLLER Primary ExaminerMervin Stein Assistant Examiner-Steven Hawkins I G l V I E lh [75] mentor 223; um mme s ausen Attorney, Agent, or Firm-Spencer & Kaye [73] Assignee: Koehring GmbH, Boppard (Rhine),

Germany [57] ABSTRACT [22] Filed: July 19, 1974 A ground compacting machine of the kind having a vibratory compacting roller in which an oscillation ex- [21] Appl' 489883 citer is located within the roller drum for causing the drum to vibrate, also has the means for driving the os- [30] Foreign Application Priority Data cillation exciter and the means for driving the roller July 24, 1973 Germany 2337532 ever the ground both located within the Teller drum. The roller drum will usually be rotatably 52 U.S. c1. 404/117; 404/122; 404/133 mounted on a hen-rotating axle and the Oscillation 51 1111. cm E01C 19/38 eiter and the roller drum may be driven from a [58] Field oi Search u 404/113 117, 122, 133 men motor mounted on the axle. The oscillation exciter and/or the drum may be coupled to the motor [56] References Cited through a centrifugal clutch, and the roller drum drive UNITED STATES PATENTS will usually include a reduction gear. The machine may comprise a single vibratory compacting roller g zhy having a steering bar connected to the axle, or at least 33427l8 9/1967 s gs 404/113 two rollers and a machine frame mounted on the rol- 3:486:427 12/1969 waschule s iii ei a ilix I: 404/117 and Providing a e for an operator and 3,670,631 6/1972 Gaylord 404/117 means for Steehhg the maehlhe- 3,778,177 12 l973 H k l. .1 404117 I a er et a l 15 Claims, 7 Drawlng Flgures is i PATENTED JUL 2 9 I975 SHEET VIBRATORY ROLLER BACKGROUND OF THE INVENTION The invention relates to a machine for compacting ground, particularly bitumen and fine sand surfaces, the machine having a vibratory compacting roller in which an oscillation exciter is mounted within the roller drum.

A conventional ground compacting vibratory roller machine usually has two roller drums and a frame or chassis carrying the means for driving the drums. Arranging the drive system on the frame of the machine gives the machine a high centre of gravity and also occupies valuable space. In particular the size of the roller drums is restricted by the space required to accommodate the drive system for the drums.

SUMMARY OF THE INVENTION With the aim of overcoming these drawbacks, according to the present invention, a ground compacting machine has a vibratory compacting roller comprising a roller drum, an oscillation exciter located within the drum for causing the drum to vibrate, means for driving the oscillation exciter to vibrate the drum, and means for driving the roller drum over the ground to be compacted, the means for driving the oscillation exciter and the means for driving the roller drum both being located within the drum.

Arranging both the means for driving the oscillation exciter and the'means for driving the roller drum inside the drum itself allows the machine frame to be made more compact with respect to the roller and also enables the centre of gravity of the machine to be lowered. Another advantage is that further rollers can, if desired, be coupled to the machine without difficulty.

BRIEF DESCRIPTION OF THE DRAWINGS Several examples of machines in accordance with the invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is an axial section through the roller of one example of a machine in accordance with the invention;

FIG. 2 is a view similar to that of FIG. 1 but illustrating the inside of the roller of a second example, the roller drum being omitted from this view;

FIG. 3 is a view similar to that of FIG. 1, but illustrating the roller of a third example;

FIG. 4 is a diagrammatic side elevation of a single roller, hand guided machine;

FIG. 5 is a diagrammatic plan view of a twin roller machine which is steered by an operator sitting on a seat provided by the machine frame;

FIG. 6 is a diagrammatic side elevation of a steerable machine having at least two axially spaced-apart rollers; and,

FIG. 7 is a view similar to FIG. 6 showing an additional roller coupled to the machine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, the roller comprises a cylindrical drum 9 supported by internal webs on roller bearings 8 which allow the drum 9 to rotate on a non-rotating hollow axle 7. The roller bearings 8 are designed to take both radial and axial thrusts, so that the drum cannot shift axially on the axle. The hollow axle 7 is preferably manufactured by cutting a tube to length and welding a flange at one end. A detachable flange is, for example, screwed to the other end, to allow the axle, with its bearings 8, to be inserted through the drum supporting webs. Fixed to the flange at one end of the axle 7 is a motor 1 whose drive shaft is coaxial with the axle and drives, through a flexible coupling 2, a rotary shaft 4 to which is fixed an unbalanced mass to act as an oscillation exciter. The rotary shaft 4 rotates in roller bearings 5 supported by webs welded internally to the hollow axle 7.

When the rotary shaft 4 rotates, the unbalanced mass produces oscillations which are transmitted through the axle 7 to the drum 9 of the roller. Mounted on the rotary shaft 4 there is a centrifugal clutch arranged so that when the shaft 4 reaches a certain rotational speed, corresponding to a certain vibration of the drum 9, the centrifugal clutch engages to drive a pulley 3. The pulley 3, acting through a V-belt I0 which passes through an opening in the wall of the hollow axle 7, drives a second pulley ll fixed to the input shaft of a reduction gear 12 attached to the outside of the axle 7. The reduction gear 12 drives a pinion 13 which meshes with a toothed ring 14 fixed to the inside of the roller drum 9. When the centrifugal clutch is engaged, the motor 1 not only drives the oscillation exciter but also drives the roller drum to cause it to rotate about the hollow axle 7 and, in use, roll over the ground to be compacted. The flange at the end of the axle 7 remote from the motor 1 is fixed to an arm 16 of the machine frame, which is not shown but can take various different forms depending on the type of machine required. For example, in the case of a one-roller machine, a steering frame or steering bar can be pivoted to the axle 7 as shown in FIG. 4. In the heavier machines shown in FIGS. 5 to 7, the roller axles 7 are fixed to the machine frame or chassis.

To protect the motor 1 and the machine frame or steering bar from the drum vibrations, rubber cushions are interposed between the terminal flanges of the axle 7 and the motor, at one end, and the machine-frame arm 16 at the other end. If the motor is fixed directly to the axle 7 a rubber disc 6 is used for absorbing vibration as shown. Between the arm 16 of the machine frame and the axle 7, however, there are interposed several rubber pads 15 to absorb the vibration. The motor I can, if desired, be mounted on a bracket, fixed to the axle 7, and in this case, several rubber cushions may be used to absorb vibration.

The interior of the axle 7 is protected against the entrance of dirt by sealing the axle at one end in dust-tight fashion to the motor housing, and at the other end in a similar fashion to the machine-frame arm 16 if this arm entirely covers the end of the axle. If not, a dusttight cover 17 is interposed as shown. The reduction gear 12, the V-belt drive 10, the pinion l3 and the toothed ring 14 are all housed between the two internal webs of the roller drum, which rotates on dust-tight bearings 8.

Instead of a V-belt drive 10 any other kind of suitable transmission from the motor 1 to the gear 12 can be used, for example a gear train, chains or friction wheels. This also applies to the drive between the reduction gear and the roller drum.

In the roller shown in FIG. 2, the motor 1 drives, through a flexible coupling 2, an intermediate shaft 18 which rotates inside a hollow rotary shaft 25 to which an unbalanced mass 26 is fixed. The intermediate shaft l8 drives both a pulley wheel 3 and the hollow rotary shaft through a centrifugal clutch. In contrast to the roller of FIG. 1 in which the motor 1 drives the rotary shaft 4 supporting the unbalanced mass directly, in the roller of FIG. 2 the motor 1 drives the shaft 25 supporting the unbalanced mass only after the centrifugal clutch has engaged. When the intermediate shaft 18 reaches a certain rotational speed the centrifugal clutch engages, allowing the intermediate shaft 18 to drive the unbalanced mass shaft 25 and create the oscillations which cause the roller drum to vibrate. The pulley 3 can, if desired, be fixed to the shaft 25, in which case the entire machine is driven forwards as soon as vibration begins, the drive being transmitted from the pulley 3 through a pulley 11 and reduction gear 12 to the drum (not shown) in the same way as in the roller of FIG. 1. The reduction gear 12 can be arranged to give forward and reverse drives. On the other hand, if desired, the pulley wheel 11 can be arranged to be free, with respect to the unbalanced mass hollow shaft 25 and the intermediate shaft 18, until the centrifugal clutch engages between the intermediate shaft 18 and the pulley wheel 3. Arranging that both the unbalanced mass hollow shaft 25 and the pulley wheel 3 are engaged simultaneously with the intermediate shaft 18 has the advantage that when the machine is at a stand still no vibration compacting of the ground takes place. Nevertheless the arrangement shown in FIG. 1 also has its advantages. Up to a certain rotational speed of the rotary shaft 4 compacting takes place without any forward drive. The operator of the machine can take advantage of this in compacting ground to a high degree where this is desired. In FIG. 2 an alternative arrangement is possible in that the pulley wheel 3 may be fixed to the intermediate shaft 18. This allows the machine to be driven over the ground without any vibration taking place.

In the roller shown in FIG. 3, a reduction gear 12 is driven directly by a motor 1 through a flexible coupling 2 and a driven shaft 18. The driven shaft 18 is arranged also to drive, through a centrifugal clutch 29, an oscillation exciter formed by an unbalanced mass. The driven shaft 18 rotates in roller bearings 27 in a nonrotating bearing housing 28 which is in the form of a cylindrical pot, one end of which houses the flexible coupling 2 and has a terminal flange to which the motor 1 is attached through a rubber cushion. The centrifugal clutch 29 is mounted on the driven shaft 18 between the reduction gear 12 and the other end of the bearing housing 28. The oscillation exciter 30 is carried by a hollow shaftwhich rotates on roller bearings 19 on the bearing housing 28.

The non-rotating bearing housing 28 is supported by a disc 20 fixed to a supporting cylinder which is itself fixed to the housing of the reduction gear 12. This gear housing is attached to a supporting tube 41 which is attached at its other end to the arm 16 of the machine frame. The members 28, 20, 40, 12, 41 together form a non-rotating assembly corresponding to the hollow axle 7 of FIGS. 1 and 2. The supporting tube 41 is coaxial with the driven shaft 18 and the bearing housing 28.

The roller drum 9 is supported by a pair of internal webs and bearings 8 for rotation about the non-rotating axle assembly, one web and bearing 8 being located on the housing 28, and the other web and bearing 8 being located on the supporting tube 41. The reduction gear 12 is arranged to drive the roller drum 9 through a pinion 13 which meshes with a gearwheel 42 fixed to the drum supporting web mounted on the tube 41.

in assembling the vibratory ground-roller of FIG. 3, either the bearing housing 28 or the supporting tube 41 can be inserted into the interior of the roller drum first. Assuming that the bearing housing 28 is inserted first and then secured to the surrounding internal web of the drum 9, the other parts of the axle assembly and drives. including the reduction gear 12, can easily be inserted through the opening of the other internal web. On the other hand, if the other parts of the axle assembly have already been inserted into the interior of the roller drum, the bearing housing 28 can easily be inserted from the other side. In either case the driven shaft 18 slides into its bearings 27, the supporting disc 20 and the oscillation exciter 30, with its bearings 27, sliding over the bearing housing 28. The oscillation exciter 30 is supported in this operation by the centrifugal clutch 29, which is mounted on the driven shaft 18. The disc 20 is keyed to the bearing housing 28, preventing the latter from rotating during operation of the vibratory ground roller. The sequence of assembly depends on which of the two internal webs of the drum 9 still have an opening free for inserting the reduction gear 12, the supporting ring 40 and the other parts of the axle assembly. In this example both of the internal supporting webs of the drum have openings to facilitate assembly. Each internal web consists of an outer ring welded to the drum, the ring having an internal diameter great enough to allow assembly of the axle shaft, and a cover plate which, after assembly, is fixed to the ring so that it closely surrounds the bearing 8 to support the drum and keep out dirt from the space between the webs.

After assembling the axle assembly in the interior of the roller drum, the motor 1 is attached to the bearing housing 28, the driving shaft of the motor being inserted into the flexible coupling 2 on the outer end of the driven shaft 18 of the reduction gear and keyed to the flexible coupling so that drive is transmitted. Finally, the arm 16 of the machine frame, or a steering bar, is attached to the other end of the axle asembly.

It should be noted that the roller shown in FIG. 3 allows the operator of the machine to drive the machine forwards or backwards up to a limiting speed of travel without vibration of the drum.

The vibratory rollers illustrated in FIGS. 1 to 3 may be used in a one-roller vibratory ground compacting machine of the kind shown in FIG. 4 or, if desired, in a machine of the kind shown in FIG. 5 in which two rollers are arranged coaxially side-by-side. In the arrangement shown in FIG. 5 the motors 1 are positioned near the outer ends of the two roller drums, to facilitate maintenance. The axles are joined together at the middle and are supported at their outer ends by the arms of a steering frame 43 of the machine, the frame having stabilising wheels and a seat for the driver.

In the one-roller vibratory ground compacting machine of FIG. 4 a steering bar 44 and legs 45 are connected to the axle, the legs preventing the bar from excessive forward swings as a reaction from the roller movement. The machine shown in FIG. 6 has a frame 46 arranged to give the vibratory ground roller an exceptionally low centre of gravity compared with similar conventional machines. As shown in FIG. 7, further rollers with frames 47, can be coupled to the main machine shown in FIG. 6.

I claim:

1. In a ground compacting machine including a vibratory compacting roller having a roller drum, an oscillation exciter located within said roller drum for causing said drum to vibrate, means for driving said oscillation exciter to vibrate said drum, and means for driving said roller drum over the ground to be compacted, the improvement wherein said means for driving said oscillation exciter and said means for driving said roller drum are both located completely within the region enclosed by the periphery and axial extremities of said drum, and include a single common drive motor having an output shaft and coupling means operatively connecting said motor shaft to said oscillation exciter and said roller drum.

2. A machine as claimed in claim 1, wherein said means for driving said oscillation exciter includes a centrifugal clutch driven by said motor.

3. A machine as claimed in claim 1, wherein said means for driving said drum over the ground includes a centrifugal clutch driven by said motor.

4. A machine as claimed in claim 1, wherein said vibratory compacting roller has a non-rotating hollow axle, said roller drum is rotatably mounted on said axle, said roller drum is rotatably mounted on said axle, and said oscillation exciter comprises an unbalanced mass and means mounting said mass within said axle for rotation about the axis of said axle and of said motor shaft.

5. A machine as claimed in claim 4, including a machine frame in the form of a steering bar, means fixing said axle to said machine frame, and vibration absorbing cushions interposed between said axle and said machine frame.

6. A machine as claimed in claim 5, wherein said vibration absorbing cushions are rubber buffers.

7. A machine as claimed in claim 4, wherein said motor is fixed to said axle, and further comprising vibration absorbing cushions interposed between said motor and said axle.

8. A machine as claimed in claim 7, wherein said motor is fixed to one end of said axle, and said machine includes a machine frame and means fixing said machine frame to the other end of said axle.

9. A machine as claimed inclaim 7, wherein said vibration absorbing cushions are rubber buffers.

10. A machine as claimed in claim 1, wherein said means for driving said drum over the ground includes a reduction gear coupled to said motor by said coupling means.

11. A machine as claimed in claim 10, wherein said reduction gear has both forward and reverse drives.

12. A machine as claimed in claim 10, wherein said reduction gear is mounted outside said axle and said means for driving said drum includes a toothed ring fixed to the inside of said roller drum. and a pinion driven by said reduction gear and meshing with said toothed ring.

13. A machine as claimed in claim 10, wherein said reduction gear includes a driven shaft aligned with the output shaft of said motor.

14. A machine as claimed in claim 13, wherein said means for driving said drum includes a gear wheel fixed to said drum, and a pinion driven by said reduction gear and meshing with said gear wheel.

15. A machine as claimed in claim 13, wherein said roller includes a non-rotating hollow axle and means mounting said roller drum for rotation on said axle, and wherein said motor is fixed to said axle and said reduction gear includes a housing which forms part of said hollow axle. 

1. In a ground compacting machine including a vibratory compacting roller having a roller drum, an oscillation exciter located within said roller drum for causing said drum to vibrate, means for driving said oscillation exciter to vibrate said drum, and means for driving said roller drum over the ground to be compacted, the improvement wherein said means for driving said oscillation exciter and said means for driving said roller drum are both located completely within the region enclosed by the periphery and axial extremities of said drum, and include a single common drive motor having an output shaft and coupling means operatively connecting said motor shaft to said oscillation exciter and said roller drum.
 2. A machine as claimed in claim 1, wherein said means for driving said oscillatioN exciter includes a centrifugal clutch driven by said motor.
 3. A machine as claimed in claim 1, wherein said means for driving said drum over the ground includes a centrifugal clutch driven by said motor.
 4. A machine as claimed in claim 1, wherein said vibratory compacting roller has a non-rotating hollow axle, said roller drum is rotatably mounted on said axle, said roller drum is rotatably mounted on said axle, and said oscillation exciter comprises an unbalanced mass and means mounting said mass within said axle for rotation about the axis of said axle and of said motor shaft.
 5. A machine as claimed in claim 4, including a machine frame in the form of a steering bar, means fixing said axle to said machine frame, and vibration absorbing cushions interposed between said axle and said machine frame.
 6. A machine as claimed in claim 5, wherein said vibration absorbing cushions are rubber buffers.
 7. A machine as claimed in claim 4, wherein said motor is fixed to said axle, and further comprising vibration absorbing cushions interposed between said motor and said axle.
 8. A machine as claimed in claim 7, wherein said motor is fixed to one end of said axle, and said machine includes a machine frame and means fixing said machine frame to the other end of said axle.
 9. A machine as claimed in claim 7, wherein said vibration absorbing cushions are rubber buffers.
 10. A machine as claimed in claim 1, wherein said means for driving said drum over the ground includes a reduction gear coupled to said motor by said coupling means.
 11. A machine as claimed in claim 10, wherein said reduction gear has both forward and reverse drives.
 12. A machine as claimed in claim 10, wherein said reduction gear is mounted outside said axle and said means for driving said drum includes a toothed ring fixed to the inside of said roller drum, and a pinion driven by said reduction gear and meshing with said toothed ring.
 13. A machine as claimed in claim 10, wherein said reduction gear includes a driven shaft aligned with the output shaft of said motor.
 14. A machine as claimed in claim 13, wherein said means for driving said drum includes a gear wheel fixed to said drum, and a pinion driven by said reduction gear and meshing with said gear wheel.
 15. A machine as claimed in claim 13, wherein said roller includes a non-rotating hollow axle and means mounting said roller drum for rotation on said axle, and wherein said motor is fixed to said axle and said reduction gear includes a housing which forms part of said hollow axle. 